Something nasty in the woodshed

What's the meaning of the phrase 'Something nasty in the woodshed'?

'Something nasty in the woodshed' is a traumatic but unspecified incident in someone's experience, or something shocking or distasteful that has been kept secret.

What's the origin of the phrase 'Something nasty in the woodshed'?

'Something nasty in the woodshed' is one of the easier phrases to provide a source for as the coinage is unambiguous. Stella Gibbons first used the expression in her 1932 comic novel Cold Comfort Farm. The phrase is used on numerous occasions in the text as it refers to a significant plot device, the supposed source of the behaviour of the deranged Aunt Ada Doom:

Flora gathered that she [Mrs. Beetle] did not altogether
disapprove of old Mrs. Starkadder. She had been
heard to say that at least there was one of ’em at Cold
Comfort as knew her own mind, even if she ’ad seen
something narsty in the woodshed when she was two.
Flora had no idea what this last sentence could possibly
mean. Possibly it was a local idiom for going cuckoo.

What Ada saw in the woodshed is not explained and the comic effect is heightened by allowing us to speculate on that for ourselves. What we do know about Stella Gibbons in real life is that she had an unhappy childhood and a father who worked from home as a doctor and was frequently unfaithful to his wife. Gibbons was educated at home in her early years and again we can speculate for ourselves what happenings she might have stumbled upon in the garden shed.

The expression 'cold comfort', meaning 'poor consolation', was of course an established expression well before Gibbons wrote her book. An early example of it in print is found in Golding's Commentary on the Psalms of David, 1571:

We receive but cold comfort of whatsoever the Scripture speaketh.

Shakespeare also used the similar terms 'cold news' and 'cold tidings' in Henry VI, Part 2 and Richard III.

Gibbons had originally intended to call the book Curse God Farm but a friend of hers knew of an actual Cold Comfort Farm near her family home in Leicestershire and suggested that it would make a better title. The property is still there, in the village of Hinkley, now renamed as Comfort Farm.